SPACE STATION FLYBYS: For the next week, the International Space Station (ISS) will be performing a series of bright evening flybys over North America and Europe. The station is very easy to see if you know when to look. Check the Simple Satellite Tracker for local flyby times or you can turn your cell phone into a field-tested ISS-tracker.

On Oct 21st, amateur astronomer Béla Vingler of Győrújfalu, Hungary, caught the space station flying directly in front of the Moon:

The station's winged outline was backlit by the bright debris fields of Crater Tycho as the spacecraft raced across the lunar disk, completing the transit in only a split-second. Because lunar transits happen so fast, careful planning is required to photograph them. The place to start is Calsky.com, which provides precise predictions of ISS transits for locations around the world.

MOON RINGS: It's not uncommon to see one ring around the Moon. But two? On Oct. 23rd, Martin Popek of Nýdek, Czech republic, photographed a rare pair:

The outer 22ocircumscribed halo is caused by moonlight shining through six-sided pencil-shaped ice crystals in the air. This is a familiar sight to backyard sky watchers. Less familiar is the 9o inner ring. It is caused by ice crystals with a strange pyramidal shape. The 9o ring is the innermost of many possible "odd-radius" halos caused by pyramidal ice crystals. Atmospheric optics expert Les Cowley notes that "pyramidal crystals [might not be as] rare as previously thought" and he urges sky watchers to "search carefully for their halos whenever the skies look favourable."

Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.